diff --git a/frontends/PyCDE/src/pycde/module.py b/frontends/PyCDE/src/pycde/module.py
index d32cf47fe7..c5791a257b 100644
--- a/frontends/PyCDE/src/pycde/module.py
+++ b/frontends/PyCDE/src/pycde/module.py
@@ -133,7 +133,7 @@ class module:
     if self.extern_mod is None:
       # Find the top MLIR module.
       mod = op
-      while mod.name != "module":
+      while mod.parent is not None:
         mod = mod.parent
 
       input_ports = [(n.value, o.type) for (n, o) in zip(op_names, op.operands)]
@@ -363,7 +363,7 @@ class _Generate:
 
     # Find the top MLIR module.
     mod = op
-    while mod.name != "module":
+    while mod.parent is not None:
       mod = mod.parent
 
     # Assemble the parameters.
diff --git a/lib/Conversion/LLHDToLLVM/LLHDToLLVM.cpp b/lib/Conversion/LLHDToLLVM/LLHDToLLVM.cpp
index 7ec41e7fcb..4bb31f1ce4 100644
--- a/lib/Conversion/LLHDToLLVM/LLHDToLLVM.cpp
+++ b/lib/Conversion/LLHDToLLVM/LLHDToLLVM.cpp
@@ -1077,7 +1077,7 @@ struct WaitOpConversion : public ConvertToLLVMPattern {
           op->getLoc(), i64Ty, transformed.time(), rewriter.getI32ArrayAttr(2));
 
       std::array<Value, 5> args({statePtr, procStateBC, realTime, delta, eps});
-      rewriter.create<LLVM::CallOp>(op->getLoc(), voidTy,
+      rewriter.create<LLVM::CallOp>(op->getLoc(), llvm::None,
                                     rewriter.getSymbolRefAttr(llhdSuspendFunc),
                                     args);
     }
@@ -1232,7 +1232,7 @@ struct InstOpConversion : public ConvertToLLVMPattern {
 
       // Add reg state pointer to global state.
       initBuilder.create<LLVM::CallOp>(
-          op->getLoc(), voidTy, rewriter.getSymbolRefAttr(allocEntityFunc),
+          op->getLoc(), llvm::None, rewriter.getSymbolRefAttr(allocEntityFunc),
           ArrayRef<Value>({initStatePtr, owner, regMall}));
 
       // Index of the signal in the entity's signal table.
@@ -1442,7 +1442,7 @@ struct InstOpConversion : public ConvertToLLVMPattern {
                                         procStateSensesPtr);
 
       std::array<Value, 3> allocProcArgs({initStatePtr, owner, procStateMall});
-      initBuilder.create<LLVM::CallOp>(op->getLoc(), voidTy,
+      initBuilder.create<LLVM::CallOp>(op->getLoc(), llvm::None,
                                        rewriter.getSymbolRefAttr(allocProcFunc),
                                        allocProcArgs);
     }
@@ -1660,7 +1660,7 @@ struct DrvOpConversion : public ConvertToLLVMPattern {
     std::array<Value, 7> args(
         {statePtr, transformed.signal(), bc, sigWidth, realTime, delta, eps});
     // Create the library call.
-    rewriter.create<LLVM::CallOp>(op->getLoc(), voidTy,
+    rewriter.create<LLVM::CallOp>(op->getLoc(), llvm::None,
                                   rewriter.getSymbolRefAttr(drvFunc), args);
 
     rewriter.eraseOp(op);
diff --git a/lib/Dialect/SV/Transforms/HWCleanup.cpp b/lib/Dialect/SV/Transforms/HWCleanup.cpp
index ec4c3d2e28..90f87b4014 100644
--- a/lib/Dialect/SV/Transforms/HWCleanup.cpp
+++ b/lib/Dialect/SV/Transforms/HWCleanup.cpp
@@ -28,20 +28,38 @@ namespace {
 /// Check the equivalence of operations by doing a deep comparison of operands
 /// and attributes, but does not compare the content of any regions attached to
 /// each op.
-struct SimpleOperationInfo : public llvm::DenseMapInfo<Operation *> {
+struct AlwaysLikeOpInfo : public llvm::DenseMapInfo<Operation *> {
   static unsigned getHashValue(const Operation *opC) {
     return mlir::OperationEquivalence::computeHash(
-        const_cast<Operation *>(opC));
+        const_cast<Operation *>(opC),
+        /*hashOperands=*/mlir::OperationEquivalence::directHashValue,
+        /*hashResults=*/mlir::OperationEquivalence::ignoreHashValue,
+        mlir::OperationEquivalence::IgnoreLocations);
   }
   static bool isEqual(const Operation *lhsC, const Operation *rhsC) {
     auto *lhs = const_cast<Operation *>(lhsC);
     auto *rhs = const_cast<Operation *>(rhsC);
+    // Trivially the same.
     if (lhs == rhs)
       return true;
+    // Filter out tombstones and empty ops.
     if (lhs == getTombstoneKey() || lhs == getEmptyKey() ||
         rhs == getTombstoneKey() || rhs == getEmptyKey())
       return false;
-    return mlir::OperationEquivalence::isEquivalentTo(lhs, rhs);
+    // Compare attributes.
+    if (lhs->getName() != rhs->getName() ||
+        lhs->getAttrDictionary() != rhs->getAttrDictionary() ||
+        lhs->getNumOperands() != rhs->getNumOperands())
+      return false;
+    // Compare operands.
+    for (auto operandPair : llvm::zip(lhs->getOperands(), rhs->getOperands())) {
+      Value lhsOperand = std::get<0>(operandPair);
+      Value rhsOperand = std::get<1>(operandPair);
+      if (lhsOperand != rhsOperand)
+        return false;
+    }
+    // The two AlwaysOps are similar enough to be combined.
+    return true;
   }
 };
 
@@ -135,7 +153,7 @@ void HWCleanupPass::runOnGraphRegion(Region &region, bool shallow) {
   // A set of operations in the current block which are mergable. Any
   // operation in this set is a candidate for another similar operation to
   // merge in to.
-  DenseSet<Operation *, SimpleOperationInfo> alwaysFFOpsSeen;
+  DenseSet<Operation *, AlwaysLikeOpInfo> alwaysFFOpsSeen;
   llvm::SmallDenseMap<Attribute, Operation *, 4> ifdefOps;
   sv::InitialOp initialOpSeen;
   sv::AlwaysCombOp alwaysCombOpSeen;
diff --git a/llvm b/llvm
index 310c9496d8..1689dade42 160000
--- a/llvm
+++ b/llvm
@@ -1 +1 @@
-Subproject commit 310c9496d80961188e8d8f8ad306cdf44bd7541f
+Subproject commit 1689dade4218945db175f7916c2261667f9bf371
diff --git a/test/CAPI/ir.c b/test/CAPI/ir.c
index e3bddb82e3..7f38f6700d 100644
--- a/test/CAPI/ir.c
+++ b/test/CAPI/ir.c
@@ -40,7 +40,7 @@ int registerOnlyHW() {
     return 2;
 
   mlirDialectHandleRegisterDialect(hwHandle, ctx);
-  if (mlirContextGetNumRegisteredDialects(ctx) != 1)
+  if (mlirContextGetNumRegisteredDialects(ctx) != 2)
     return 3;
   if (mlirContextGetNumLoadedDialects(ctx) != 1)
     return 4;
diff --git a/test/Conversion/FIRRTLToHW/lower-to-hw-errors.mlir b/test/Conversion/FIRRTLToHW/lower-to-hw-errors.mlir
index f92e3de0c8..fbfe2adc9e 100644
--- a/test/Conversion/FIRRTLToHW/lower-to-hw-errors.mlir
+++ b/test/Conversion/FIRRTLToHW/lower-to-hw-errors.mlir
@@ -15,7 +15,7 @@ firrtl.circuit "InvalidBundle" {
     %0 = firrtl.invalidvalue : !firrtl.bundle<inp_d: uint<14>>
   }
 
-  // expected-error @+1 {{unexpected operation 'func' in a firrtl.circuit}}
+  // expected-error @+1 {{unexpected operation 'builtin.func' in a firrtl.circuit}}
   func private @UnknownFunction() {
     return
   }
diff --git a/test/Conversion/FIRRTLToHW/lower-to-hw-module.mlir b/test/Conversion/FIRRTLToHW/lower-to-hw-module.mlir
index 1ad9149b97..271669bf4a 100644
--- a/test/Conversion/FIRRTLToHW/lower-to-hw-module.mlir
+++ b/test/Conversion/FIRRTLToHW/lower-to-hw-module.mlir
@@ -2,7 +2,7 @@
 
 // The firrtl.circuit should be removed, the main module name moved to an
 // attribute on the module.
-// CHECK-LABEL: {{^}}module attributes {firrtl.mainModule = "Simple"} {
+// CHECK-LABEL: {{^}}builtin.module attributes {firrtl.mainModule = "Simple"} {
 // CHECK-NOT: firrtl.circuit
 
 // We should get a large header boilerplate.
diff --git a/test/Conversion/LLHDToLLVM/convert_signals.mlir b/test/Conversion/LLHDToLLVM/convert_signals.mlir
index fffac95941..3f52abe4cc 100644
--- a/test/Conversion/LLHDToLLVM/convert_signals.mlir
+++ b/test/Conversion/LLHDToLLVM/convert_signals.mlir
@@ -83,7 +83,7 @@ llhd.entity @convert_prb (%sI1 : !llhd.sig<i1>, %sArr : !llhd.sig<!llhd.array<3x
 // CHECK:           %[[VAL_18:.*]] = llvm.extractvalue %[[VAL_13]][0 : i32] : !llvm.array<3 x i64>
 // CHECK:           %[[VAL_19:.*]] = llvm.extractvalue %[[VAL_13]][1 : i32] : !llvm.array<3 x i64>
 // CHECK:           %[[VAL_20:.*]] = llvm.extractvalue %[[VAL_13]][2 : i32] : !llvm.array<3 x i64>
-// CHECK:           %[[VAL_21:.*]] = llvm.call @driveSignal(%[[VAL_0]], %[[VAL_4]], %[[VAL_17]], %[[VAL_14]], %[[VAL_18]], %[[VAL_19]], %[[VAL_20]]) : (!llvm.ptr<i8>, !llvm.ptr<struct<(ptr<i8>, i64, i64, i64)>>, !llvm.ptr<i8>, i64, i64, i64, i64) -> !llvm.void
+// CHECK:           llvm.call @driveSignal(%[[VAL_0]], %[[VAL_4]], %[[VAL_17]], %[[VAL_14]], %[[VAL_18]], %[[VAL_19]], %[[VAL_20]]) : (!llvm.ptr<i8>, !llvm.ptr<struct<(ptr<i8>, i64, i64, i64)>>, !llvm.ptr<i8>, i64, i64, i64, i64) -> ()
 // CHECK:           %[[VAL_22:.*]] = llvm.mlir.constant(1 : i32) : i32
 // CHECK:           %[[VAL_23:.*]] = llvm.mlir.constant(8 : i64) : i64
 // CHECK:           %[[VAL_24:.*]] = llvm.mlir.null : !llvm.ptr<array<3 x i5>>
@@ -97,7 +97,7 @@ llhd.entity @convert_prb (%sI1 : !llhd.sig<i1>, %sArr : !llhd.sig<!llhd.array<3x
 // CHECK:           %[[VAL_31:.*]] = llvm.extractvalue %[[VAL_13]][0 : i32] : !llvm.array<3 x i64>
 // CHECK:           %[[VAL_32:.*]] = llvm.extractvalue %[[VAL_13]][1 : i32] : !llvm.array<3 x i64>
 // CHECK:           %[[VAL_33:.*]] = llvm.extractvalue %[[VAL_13]][2 : i32] : !llvm.array<3 x i64>
-// CHECK:           %[[VAL_34:.*]] = llvm.call @driveSignal(%[[VAL_0]], %[[VAL_6]], %[[VAL_30]], %[[VAL_27]], %[[VAL_31]], %[[VAL_32]], %[[VAL_33]]) : (!llvm.ptr<i8>, !llvm.ptr<struct<(ptr<i8>, i64, i64, i64)>>, !llvm.ptr<i8>, i64, i64, i64, i64) -> !llvm.void
+// CHECK:           llvm.call @driveSignal(%[[VAL_0]], %[[VAL_6]], %[[VAL_30]], %[[VAL_27]], %[[VAL_31]], %[[VAL_32]], %[[VAL_33]]) : (!llvm.ptr<i8>, !llvm.ptr<struct<(ptr<i8>, i64, i64, i64)>>, !llvm.ptr<i8>, i64, i64, i64, i64) -> ()
 // CHECK:           llvm.return
 // CHECK:         }
 llhd.entity @convert_drv (%sI1 : !llhd.sig<i1>, %sArr : !llhd.sig<!llhd.array<3xi5>>) -> () {
@@ -116,7 +116,7 @@ llhd.entity @convert_drv (%sI1 : !llhd.sig<i1>, %sArr : !llhd.sig<!llhd.array<3x
 // CHECK:           llvm.cond_br %[[VAL_19]], ^bb1, ^bb2
 // CHECK:         ^bb1:
 
-// CHECK:           %{{.*}} = llvm.call @driveSignal
+// CHECK:           llvm.call @driveSignal
 // CHECK:           llvm.br ^bb2
 // CHECK:         ^bb2:
 // CHECK:           llvm.return
@@ -195,7 +195,7 @@ llhd.entity @convert_drv_enable (%sI1 : !llhd.sig<i1>) -> () {
 // CHECK:           %[[VAL_49:.*]] = llvm.extractvalue %[[VAL_41]][0 : i32] : !llvm.array<3 x i64>
 // CHECK:           %[[VAL_50:.*]] = llvm.extractvalue %[[VAL_41]][1 : i32] : !llvm.array<3 x i64>
 // CHECK:           %[[VAL_51:.*]] = llvm.extractvalue %[[VAL_41]][2 : i32] : !llvm.array<3 x i64>
-// CHECK:           %[[VAL_52:.*]] = llvm.call @driveSignal(%[[VAL_0]], %[[VAL_6]], %[[VAL_48]], %[[VAL_43]], %[[VAL_49]], %[[VAL_50]], %[[VAL_51]]) : (!llvm.ptr<i8>, !llvm.ptr<struct<(ptr<i8>, i64, i64, i64)>>, !llvm.ptr<i8>, i64, i64, i64, i64) -> !llvm.void
+// CHECK:           llvm.call @driveSignal(%[[VAL_0]], %[[VAL_6]], %[[VAL_48]], %[[VAL_43]], %[[VAL_49]], %[[VAL_50]], %[[VAL_51]]) : (!llvm.ptr<i8>, !llvm.ptr<struct<(ptr<i8>, i64, i64, i64)>>, !llvm.ptr<i8>, i64, i64, i64, i64) -> ()
 // CHECK:           llvm.br ^bb8
 // CHECK:         ^bb8:
 // CHECK:           llvm.br ^bb9
diff --git a/test/Conversion/LLHDToLLVM/convert_simple.mlir b/test/Conversion/LLHDToLLVM/convert_simple.mlir
index 84c74417be..627f266a06 100644
--- a/test/Conversion/LLHDToLLVM/convert_simple.mlir
+++ b/test/Conversion/LLHDToLLVM/convert_simple.mlir
@@ -32,7 +32,7 @@
 // CHECK:           %[[VAL_24:.*]] = llvm.extractvalue %[[VAL_19]][0 : i32] : !llvm.array<3 x i64>
 // CHECK:           %[[VAL_25:.*]] = llvm.extractvalue %[[VAL_19]][1 : i32] : !llvm.array<3 x i64>
 // CHECK:           %[[VAL_26:.*]] = llvm.extractvalue %[[VAL_19]][2 : i32] : !llvm.array<3 x i64>
-// CHECK:           %[[VAL_27:.*]] = llvm.call @driveSignal(%[[VAL_0]], %[[VAL_5]], %[[VAL_23]], %[[VAL_20]], %[[VAL_24]], %[[VAL_25]], %[[VAL_26]]) : (!llvm.ptr<i8>, !llvm.ptr<struct<(ptr<i8>, i64, i64, i64)>>, !llvm.ptr<i8>, i64, i64, i64, i64) -> !llvm.void
+// CHECK:           llvm.call @driveSignal(%[[VAL_0]], %[[VAL_5]], %[[VAL_23]], %[[VAL_20]], %[[VAL_24]], %[[VAL_25]], %[[VAL_26]]) : (!llvm.ptr<i8>, !llvm.ptr<struct<(ptr<i8>, i64, i64, i64)>>, !llvm.ptr<i8>, i64, i64, i64, i64) -> ()
 // CHECK:           llvm.return
 // CHECK:         }
 
diff --git a/test/Conversion/LLHDToLLVM/convert_wait.mlir b/test/Conversion/LLHDToLLVM/convert_wait.mlir
index 3f0867b368..2af6fbb1ea 100644
--- a/test/Conversion/LLHDToLLVM/convert_wait.mlir
+++ b/test/Conversion/LLHDToLLVM/convert_wait.mlir
@@ -33,7 +33,7 @@
 // CHECK:           %[[VAL_19:.*]] = llvm.extractvalue %[[VAL_11]][0 : i32] : !llvm.array<3 x i64>
 // CHECK:           %[[VAL_20:.*]] = llvm.extractvalue %[[VAL_11]][1 : i32] : !llvm.array<3 x i64>
 // CHECK:           %[[VAL_21:.*]] = llvm.extractvalue %[[VAL_11]][2 : i32] : !llvm.array<3 x i64>
-// CHECK:           %[[VAL_22:.*]] = llvm.call @llhdSuspend(%[[VAL_0]], %[[VAL_18]], %[[VAL_19]], %[[VAL_20]], %[[VAL_21]]) : (!llvm.ptr<i8>, !llvm.ptr<i8>, i64, i64, i64) -> !llvm.void
+// CHECK:           llvm.call @llhdSuspend(%[[VAL_0]], %[[VAL_18]], %[[VAL_19]], %[[VAL_20]], %[[VAL_21]]) : (!llvm.ptr<i8>, !llvm.ptr<i8>, i64, i64, i64) -> ()
 // CHECK:           llvm.return
 // CHECK:         ^bb4:
 // CHECK:           %[[VAL_23:.*]] = llvm.mlir.constant(0 : i32) : i32
@@ -168,7 +168,7 @@ llhd.proc @convert_resume_observe_partial (%in0 : !llhd.sig<i1>, %in1 : !llhd.si
 // CHECK:           %[[VAL_25:.*]] = llvm.extractvalue %[[VAL_13]][0 : i32] : !llvm.array<3 x i64>
 // CHECK:           %[[VAL_26:.*]] = llvm.extractvalue %[[VAL_13]][1 : i32] : !llvm.array<3 x i64>
 // CHECK:           %[[VAL_27:.*]] = llvm.extractvalue %[[VAL_13]][2 : i32] : !llvm.array<3 x i64>
-// CHECK:           %[[VAL_28:.*]] = llvm.call @llhdSuspend(%[[VAL_0]], %[[VAL_24]], %[[VAL_25]], %[[VAL_26]], %[[VAL_27]]) : (!llvm.ptr<i8>, !llvm.ptr<i8>, i64, i64, i64) -> !llvm.void
+// CHECK:           llvm.call @llhdSuspend(%[[VAL_0]], %[[VAL_24]], %[[VAL_25]], %[[VAL_26]], %[[VAL_27]]) : (!llvm.ptr<i8>, !llvm.ptr<i8>, i64, i64, i64) -> ()
 // CHECK:           llvm.return
 // CHECK:         ^bb4:
 // CHECK:           %[[VAL_29:.*]] = llvm.mlir.constant(0 : i32) : i32
diff --git a/test/circt-opt/commandline.mlir b/test/circt-opt/commandline.mlir
index b044be5286..014e493f7e 100644
--- a/test/circt-opt/commandline.mlir
+++ b/test/circt-opt/commandline.mlir
@@ -5,6 +5,7 @@
 
 // DIALECT: Available Dialects:
 // DIALECT-NEXT: affine
+// DIALECT-NEXT: builtin
 // DIALECT-NEXT: calyx
 // DIALECT-NEXT: comb
 // DIALECT-NEXT: esi
diff --git a/tools/firtool/firtool.cpp b/tools/firtool/firtool.cpp
index c35ede3e38..27bd427514 100644
--- a/tools/firtool/firtool.cpp
+++ b/tools/firtool/firtool.cpp
@@ -35,6 +35,7 @@
 #include "mlir/Transforms/GreedyPatternRewriteDriver.h"
 #include "mlir/Transforms/Passes.h"
 #include "llvm/Support/CommandLine.h"
+#include "llvm/Support/FileSystem.h"
 #include "llvm/Support/InitLLVM.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/SourceMgr.h"
diff --git a/tools/llhd-sim/llhd-sim.cpp b/tools/llhd-sim/llhd-sim.cpp
index a1d29ff2fd..1957a9db10 100644
--- a/tools/llhd-sim/llhd-sim.cpp
+++ b/tools/llhd-sim/llhd-sim.cpp
@@ -24,6 +24,7 @@
 #include "mlir/Target/LLVMIR/Export.h"
 #include "mlir/Transforms/Passes.h"
 
+#include "llvm/Support/Error.h"
 #include "llvm/Support/InitLLVM.h"
 #include "llvm/Support/SourceMgr.h"
 #include "llvm/Support/ToolOutputFile.h"